M. Lessard et al., CELL-MEDIATED AND HUMORAL IMMUNE-RESPONSES IN CHICKENS INFECTED WITH SALMONELLA-TYPHIMURIUM, Avian diseases, 39(2), 1995, pp. 230-238
The cellular immune responses of leghorn and New Hampshire chickens fo
llowing oral challenge at 4 weeks of age with Salmonella typhimurium w
ere measured using assays for lymphocyte proliferative responses to mi
togens and cytotoxic activity of natural killer (NK) cells. In additio
n, the humoral immune response to Newcastle disease virus (NDV) vaccin
e was assessed in S. typhimurium-infected chickens. At 8 and 20 days a
fter infection with S. typhimurium, lymphocyte proliferative responses
to various mitogens were significantly higher in S. typhimurium-infec
ted chickens than in uninfected birds of the same breeds. Cytotoxic ac
tivity of NK cells was also significantly increased in infected birds
on these days. Thirteen days after S. typhimurium infection, infected
NDV vaccinated chickens had higher antibody titers in response to NDV
vaccination than uninfected vaccinated birds. NDV titers did not diffe
r among groups at any other time of testing. These results show that b
oth cellular and humoral immune functions are activated in the first 3
weeks following infection of 4-week-old chickens with S. typhimurium.